Gateway/Network Address confusion [7:36400]
Trying to apply what I am learning in the CCNA class, I am running into some confusion regarding some basic concepts. I am trying to apply what I learned to our network which has a few colocated customers to whom I want to assign ips with subnets. We have a /23 assigned to us, let us call it 63.142.136.0/23. We have broken it up into (assigned on our router's etherne port): Internet address is 63.142.136.1/24 Secondary address 63.142.137.1/24 Also, show ip route static shows (among other things): S 63.142.136.0/23 is directly connected, Null0 S* 0.0.0.0/0 [1/0] via 66.100.223.193 Now here is where my confusion begins. I want to assign a subnet to a customer, let us say 63.142.136.32/27 which will be 32 - 63 with 32 being the network address and 63 being the broadcast. I will then add ip route 63.142.136.32 255.255.255.224 On his Windows server, do I assign 63.142.136.33 as the default gateway? and now do I need to add a route to route his subnet to 63.142.136.1? Am I confused about the Gateway vs. network address? If I could understand this, I think I would understand everything about routing. :-) Well maybe not, but I sure would feel better about it... Thanx, Anil Gupte Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=36400t=36400 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Gateway/Network Address confusion [7:36400]
OK, some terminology. We've got physical networks. They are bound by routers. Anytime a packet goes through a router, it is moving from one physical network to another. Then you have a logical subnet. This is what actually gets addressed. It is possible to have multiple logical subnets on one physical network, although not recommended. Each device can only directly communicate with other members of the same logical subnet. A router would have to translate between the two logical subnets. Now, in the scenario you described, you have two logical subnets on one physical network (that's what the secondary address does). Also, the two logical subnets consume all your address space. You mentioned partitioning off subnets for customers. Does this mean each customer gets a seperate physical network? And do you need to provision networks for WAN links? Here would be one way to do it. Take the .137.X network off the main router (Call it R1). Get a second router (R2) for this customer. Setup a point-to-point connection between the two. Now, R1-E0 has an address of 63.142.136.1/24. Assign R1-S0 to 63.142.137.1/30 and R2-S0 to 63.142.137.2/30. This is the WAN connection. Then on R2-E0, assign address 63.142.137.33/27. The default gateway for the hosts on this network would be 63.142.137.33 and the broadcast would be 63.142.137.63. And on a correct built network, the hosts (servers) never need to have route add commands. Now if you are doing this all on one router, you just need to add a secondary address of 63.142.137.33/27 (this would require you take off the 63.142.137.1/24 address first). This creates a logical subnet on your existing physical network. I hope this made some sense to you. If you have questions, I'll be lurking around here somewhere. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=36421t=36400 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Gateway/Network Address confusion [7:36400]
You said: It is possible to have multiple logical subnets on one physical network, although not recommended. Why not? The purpose here is to keep customers from stealing Ips that are not theirs and causing IP conflicts (Windows Servers die when that happens). Also, it prevents at least for low level crackers, the ability to crack into a domain/machine if they are on different logical subnets. They are on the same wire in that they all come off the same switch which in turn is connected to the Ethernet on the router. In your exmaple of the two router configuration, (Then on R2-E0, assign address 63.142.137.33/27. ...), how would packets know how to get to 63.142.137.2/30 from the .33 gateway). Sorry for the dumb wuestions, but that is how I learn. Thanx for your detailed explanations. Anil Gupte - Original Message - From: Chris Charlebois To: Sent: Monday, February 25, 2002 1:25 PM Subject: RE: Gateway/Network Address confusion [7:36400] OK, some terminology. We've got physical networks. They are bound by routers. Anytime a packet goes through a router, it is moving from one physical network to another. Then you have a logical subnet. This is what actually gets addressed. It is possible to have multiple logical subnets on one physical network, although not recommended. Each device can only directly communicate with other members of the same logical subnet. A router would have to translate between the two logical subnets. Now, in the scenario you described, you have two logical subnets on one physical network (that's what the secondary address does). Also, the two logical subnets consume all your address space. You mentioned partitioning off subnets for customers. Does this mean each customer gets a seperate physical network? And do you need to provision networks for WAN links? Here would be one way to do it. Take the .137.X network off the main router (Call it R1). Get a second router (R2) for this customer. Setup a point-to-point connection between the two. Now, R1-E0 has an address of 63.142.136.1/24. Assign R1-S0 to 63.142.137.1/30 and R2-S0 to 63.142.137.2/30. This is the WAN connection. Then on R2-E0, assign address 63.142.137.33/27. The default gateway for the hosts on this network would be 63.142.137.33 and the broadcast would be 63.142.137.63. And on a correct built network, the hosts (servers) never need to have route add commands. Now if you are doing this all on one router, you just need to add a secondary address of 63.142.137.33/27 (this would require you take off the 63.142.137.1/24 address first). This creates a logical subnet on your existing physical network. I hope this made some sense to you. If you have questions, I'll be lurking around here somewhere. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=36471t=36400 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
